The present embodiments relate to ink compositions suitable for printing marks or images on deformable substrates. In particular, disclosed herein is a stretchable water-based ink composition. These ink compositions can be used for ink jet printing.
Printing marks or images on deformable substrates is desirable for many applications, such as flexible medical devices, including surgical tools and implantable medical devices, robot skins, textiles (e.g., for stretchable swimming suits), rubber products such as tires, tubes, and cables, and the like. Consumable products based on rubbers and some textiles are also stretchable. Because of the highly deformable characteristic of the substrate, a stretchable ink is desired for printing on such substrates to achieve excellent image quality, image robustness, and image longevity.
Previous work by the inventors includes a stretchable ink composition which comprises water, a colorant, a surfactant, and a fluoroelastomer, as disclosed in U.S. patent application Ser. No. 13/182,579 to Wu et al., filed on Jul. 14, 2011, which is hereby incorporated by reference herein in its entirety.
U.S. patent application Ser. No. 13/495,915, which is hereby incorporated by reference herein in its entirety, of Wu et al., describes in the Abstract thereof an ink composition suitable for ink jet printing, including printing on deformable substrates. In embodiments, the stretchable ink composition is based on an aqueous ink formulation comprising an emulsion of a polyurethane elastomer in combination with colorant dispersions, and surfactants.
Water-based latex inks have been proposed. Certain water-based latex inks comprise water, water-miscible co-solvent, latex particles, and colorant such as pigment particles. For example, certain wide-format ink jet printers employ latex inks. The inks are cured inside the printer using radiant heat and forced air to coalesce latex particles into a film that encapsulates the pigments and bonds to print media. While robust images can be formed on normal paper or coated paper with such inks, there remains a need for a latex ink that can be successfully used on deformable materials which are used for many applications such as flexible medical devices, robot skins, textiles (e.g. for stretchable swimming suits), rubber products including tires, tubes, and cables. Due to the highly deformable characteristic of the substrate materials, a stretchable ink, preferably with pigment colorants, is desirable that can print on deformable substrates while achieving excellent image robustness and image longevity. Current latex inks are not stretchable. Further, current latex inks are generally based on acrylate resin which can be cost prohibitive.
While known compositions and processes are suitable for their intended purposes, a need remains for improved ink compositions with certain characteristics. Specifically, a need remains for ink compositions suitable for printing on deformable or stretchable substrates. Additionally, a need remains for stretchable inks that form robust images which can be stretched and relaxed for a high number of cycles. There is also a need for stretchable inks that have good color stability. There is also a need for stretchable inks that exhibit good resistance to environmental factors such as light, chemicals, water, and oxidizing gases, thus generating hydrophobic and water-resistant images. There further remains a need for stretchable inks that are suitable for both indoor and outdoor applications. There further remains a need for such inks can be applied digitally.
The appropriate components and process aspects of the each of the foregoing U.S. Patents and Patent Publications may be selected for the present disclosure in embodiments thereof. Further, throughout this application, various publications, patents, and published patent applications are referred to by an identifying citation. The disclosures of the publications, patents, and published patent applications referenced in this application are hereby incorporated by reference into the present disclosure to more fully describe the state of the art to which this invention pertains.